With the rapid development of Internet and the popularization of large-screen multi-functional mobile phones, a large number of mobile data multimedia services and various high bandwidth multimedia services appear, such as, video conference, TV broadcast, video on demand, video advertisement, network education, interactive game, and so on, which not only meet the increasing service requirements of the mobile user but also bring new service growth points to the mobile operators. These mobile data multimedia services require that a plurality of users are able to simultaneously receive the same data, and compared with common data services, the mobile data multimedia services have features of mass of data, long duration, and delay-sensitive, and so on.
In order to effectively use mobile network resources, the 3rd Generation Partnership Project (3GPP) proposes an MBMS service, and the MBMS service is a technology of transmitting data from a data source to a plurality of targets, which achieves resource sharing of networks including a core network and an access network and improves the utilization rate of the network resources, especially air interface resources. The MBMS service defined by 3GPP not only can achieve multicasting and broadcasting of message classes with plain text and low rate, but also can achieve broadcasting and multicasting of high speed multimedia services and provide various rich video, audio and multimedia services, which undoubtedly conforms to the development trend of future mobile data and provides a better service prospect for the development of 3rd Generation (3G) digital communication.
At present, the MBMS service is introduced into an LTE R9 system. Bearing the MBMS service in the system is required to achieve by the common transmission of a control signaling and user data. The control signaling notifies the terminal, for example, receives the corresponding control parameters of a terminal, a user equipment (UE), etc., and directs the terminal to receive its interested MBMS service (i.e., the corresponding user data) at a corresponding position. Such control signaling is transmitted via a multicast control channel (MCCH) in the LTE R9 system.
The MBMS services can be performed area division according to MBSFN areas (i.e., MBSFN Area), wherein, the MBSFN Area consists of a series of cells, and when a cell in the MBSFN Area sends the control signaling and the user data, it bears out synchronous sending by using a multimedia broadcast multicast service single frequency network (MBSFN) technology, so that the UE can obtain the corresponding combination gain upon receiving. A certain particular area may be covered by a plurality of MBSFN Areas synchronously, which is the so-called MBSFN Area overlapping coverage, and that particular cell is a cell covered by a plurality of MBSFN Areas in an overlapping way. At present, the cell can support the overlapping coverage of 1 to 8 MBSFN Areas.
When there is an overlapping coverage situation in a certain cell, that cell may have a plurality of logic channels, MCCHs, simultaneously, that is because each MBSFN Area corresponds to one MCCH. However, for each MCCH, there is a modification period of the MCCH, and within the duration of the modification period of the MCCH, the contents bore by the MCCH are not allowed to be changed; and within the duration of the modification period of the MCCH, the MCCH information will also be sent repeatedly, wherein the time interval for sending is referred to as a repeat period of MCCH, and the repeated sending with the repeat period of MCCH is mainly for improving the reliability of the UE receiving the MCCH information.
The relationship between the modification period and the repeat period of the MCCH is shown in FIG. 1, wherein the modification period of the MCCH is represented as MCCH MP, the repeat period of the MCCH is represented as MCCH RP. In MCCH MP(n), the contents sent by the MCCH cannot be changed and can only be changed until the next MCCH MP, and the MCCH RP represents the repeated sending of the content of the MCCH in the MCCH MP. The UE can acquire all the MCCHs and its corresponding configuration information in the cell through a system information block (SIB) of a broadcast control channel (BCCH) and in particular through the SIB 13, such as corresponding parameters of how may MCCHs in that cell, the modification period of each MCCH, the repeat period of each MCCH, etc.
There is a one-to-one correspondence between the MCCH and the MBSFN Area; and the UE can acquire the control information about the MBSFN Area corresponding to the logic channel MCCH by receiving an MCCH message bore on the logic channel MCCH, for example, the configuration information about multicast subframe resources of that MBSFN Area, all the MBMS services which has completed MBMS Session Start procedure in that MBSFN Area, control parameters of those MBMS services which has completed MBMS Session Start procedure, and so on. The MBMS service with Session Start is the MBMS service which has already started sending by a network, and the control parameters of the MBMS service which has completed MBMS Session Start procedure include parameters such as MBMS-SessionInfo-r9, sessionId-r9, serviceId-r9, etc.
The features of the MBMS service is as follows: data amount of the service is large, the receiving duration of the terminal is long, and the average data rate is relatively constant. The above features decide that both scheduling of the MBMS service and the configuration of the control signaling are semi-static, that is, the scheduling information about the MBMS service and the control signaling information remain unchanged for long term. Thus, the MCCH information sent by the system all the time may be information which is not changed for a long time. Thus, for a terminal which has already obtained the MCCH information, if it receives every time the MCCH information which is not changed, the terminal will waste electricity, that is because the information amount of the MCCH is large, and a receiving and parsing process is relatively power consumptive. The “long term” regarding the control signaling information remains unchanged for long term generally refers to the time length of several seconds or several minutes; and the “sending all the time” regarding the MCCH information which is sent by the system all the time is in that a new user may access at any time.
Therefore, the introduction of an MBMS notification message is proposed. The MBMS notification message can describe with few information whether the MCCH information to be sent within the next MCCH modification period is updated as compared to the MCCH information sent within the current MCCH modification period. The UE only needs to monitor few information about the MBMS notification message, and the terminal then decides whether to receive the coming MCCH information according to the MBMS notification message. Aiming at the English description of the MBMS notification message, some companies call it as MCCH change notification, or MCCH notification, or MBMS notification Indicator, or MBMS notification information, or MBMS notification, and aiming at the Chinese description of the MBMS notification message, some companies call it as MBMS notification message, or MBMS notification information, or MBMS indication information, etc.; and in the subsequent description hereinafter, it is uniformly referred to as MBMS notification message in Chinese and MCCH notification in English for describing.
The specific sending position of the MBMS notification message (MCCH notification) is notified by the SIB 13 in the broadcast control channel (BCCH); and the MCCH notification is sent for several times within the modification period of the MCCH, or can also be once, and the specific position information and information about the number of times for sending are included in the SIB 13, as shown in FIG. 2.
When there is the overlapping coverage situation in the cell, for all the MCCHs in the cell a uniform MCCH notification is used to indicate a change situation of a plurality of MCCHs, which is specifically that:
the MCCH notification will indicate which one MCCH is changed or which MCCHs are changed through payload of the MCCH notification, wherein the payload of the MCCH notification is 8 bits and correspondingly supports the indication of the information about 8 MCCHs at most, and wherein it is notified that which bit in the payload of the specific MCCH notification represents the information about which MCCH by the system information block SIB13 in the BCCH. In order to describe the process of MCCH notification more clearly, a specific example is taken as follows. As shown in FIG. 3, the UE acquires that the 3rd bit in the payload of the MCCH notification represents MBSFN Areal by the SIB13, and taking the relation of one-to-one correspondence between the MBSFN Area and the MCCH into consideration, therefore the 3rd bit in the payload of the MCCH notification will represent whether the MCCH1 information is changed; if the UE monitoring the MCCH notification finds that the 3rd bit is “1”, it indicates that its corresponding MCCH1 information has changed, and if the UE monitoring the MCCH notification finds that the 3rd bit is “0”, it indicates that its corresponding MCCH1 information has not changed; of course, the meanings represented by “1” and “0” can be interchanged, that is, “1” represents that the corresponding MCCH1 information has changed, and “0” represents that the corresponding MCCH1 information has not changed. Thus, the UE can realize to monitor whether the corresponding MCCH1 information has changed by monitoring the MCCH notification.
Further, according to the above contents, a certain bit in the payload of the MCCH notification corresponds to whether the corresponding MCCH information is changed, for example, “1” represents that it is changed, and “0” represents that it is not changed. However, the corresponding bit in the payload of the MCCH notification will not indicate that any MCCH information is changed. At present, the MCCH notification only indicates the change of the MCCH information triggered by the Session Start of the MBMS service, but other change reasons of the MCCH message, such as Session Stop, Session Update, will not trigger the indication of the payload of the MCCH notification. For example, the MCCH information is changed due to Session Stop or Session Update, the corresponding bit of the payload of the MCCH notification will not indicate that the MCCH information is changed, so that the UE monitoring the MCCH notification also cannot acquire that the corresponding MCCH information has changed. In summary, the current MCCH notification can only reflect the Session Start of the MBMS service and the Session Start of the MBMS(s) of which MBSFN Area(s) has happened; that is to say, the change of these three types of information in the MCCH message will not be embodied in the MCCH Notification: 1) the configuration information about the MCCH is changed, for example, the configuration information of the MBSFN subframe of an MBSFN area is changed; 2) Session Update and Session Stop of the MBMS service; and 3) Session Start of which specific MBMS service occurs.
In conclusion, various related arts involving MBMS services above neither reveals an implementation of how to obtain a cell service list nor an implementation of how to receive the MBMS service data after obtaining the cell service list.